/*

Sandra N. Kardaras-Flick
03/18/05

LINKED LISTS

A program which reads a list of integers from the keyboard, 
creates a linked list out of them, and prints the result.
 
*/


#include <stdio.h>
#include <stdlib.h>

/*Global Declarations */
typedef int KEY_TYPE;

typedef struct
   {
    KEY_TYPE key;
    /* Other data goes here */
   } DATA;

typedef struct nodeTag
   {
    DATA            data;
    struct nodeTag *link;
   } NODE;

/*Prototype Declarations */
void printList (NODE * pList);

int main (void)
{
/*Local Definitions */
int   num;
NODE *pList = NULL;
NODE *pNew;
NODE *pRear = NULL;

/*Statements */

/* Insert first node into linked list */
printf ("\n\n\nEnter a list of numbers for a linked list.\nEnd your list with EOF:\n\n");

while (scanf ("%d", &num) == 1)
   {
    pNew = (NODE *) malloc (sizeof (NODE));
    if (!pNew)
       {
        printf ("\aCan not allocate node.\n");
        return 100;
       } /* if */

    pNew->data.key = num;
    pNew->link     = NULL;

    if (pList == NULL) /* first node */
       pList = pRear = pNew;
    else /* other nodes */
       {
        pRear->link = pNew;
        pRear       = pNew;
       } /* else */
   } /* while */
printf ("\nLinked list complete.\n");

printList (pList);


return 0;
}/* main */

/*================== printList =====================
Traverse and print the keys from a linked list
   Pre:   pList is a valid linked list 
   Post:  Keys of list have been printed 
*/
void printList (NODE *pList)
{
/*Local Definitions */
NODE *pWalker;
int lineCount = 0;

/*Statements */
pWalker = pList;
printf ("\nList contains:\n");

while (pWalker)
   {
    if (++lineCount > 10)
       {
        lineCount = 1;
        printf ("\n");
       } /* if */
    printf ("%d => ", pWalker->data.key);
    pWalker = pWalker->link;
   } /* while */
printf ("<End of List>\n\n");
return;
}/* printList */